Stocks aren't the only bargains in this recession: Travel companies are slashing prices on flights, cruises, and hotel rooms to get you to loosen your purse strings.

Low-fare carrier Southwest Airlines Co. is offering a 50 percent reduction in airfares to Seattle. Princess Cruises is promoting a "2-for-1 Escape the Economy" sale on nearly 200 European or Alaskan sailings. And many of the ultra-luxurious Four Seasons hotels are dangling the third, fourth, or fifth night for free.

"The deals are out there because fewer people are traveling," said Genevieve Shaw Brown, senior editor at Travelocity.com, a travel-booking website. "So for people who have the means to take a vacation, this is the best time in years to do it."

The travel industry is responding as Americans cut back on discretionary spending and travel less. The US Travel Association forecasts the country's volume of domestic trips - when one person travels at least 50 miles from home or spends at least one night away from home - will slide 1.9 percent this year from 2008. Meanwhile, the volume of overseas visits to the United States is projected to fall 3.1 percent from last year.

As a result, some carriers are deeply discounting airfares.

This week, Southwest launched its three-day "Wanna Get Away" sale, which ends today at midnight, for all round-trip flights to or from Seattle between Feb. 3 and May 31. The half-off fares - which reduce the price of a flight between Providence and Seattle to as low as $95 each way - are the deepest discounts Southwest offers during the post-holiday winter lull.

"This is traditionally one of the softer times of the year," said airline spokesman Paul Flaningan. "We're trying to stimulate some travel."

Low-cost carrier AirTran Airways also shot off a three-day systemwide sale on Tuesday. The savings on Boston flights, booked by midnight for travel through March 11 to Florida and San Juan or through May 20 for all other destinations, range from 18 percent off for folks headed to Charleston, S.C., to 55 percent off to Atlanta.

"It's really just a way of getting people thinking about traveling again," said AirTran spokeswoman Judy Graham-Weaver. "After the holidays, people don't think about it much. And with the economy the way it is, people are thinking about it less."

The travel bargains aren't bound by the nation's borders. One of the best deals is a trip to Britain, said Anne Banas, executive editor of Smarter Travel Media.

British Airways launched a sale Tuesday that offers round-trip airfare from Boston and two nights of London hotel accommodations starting at $515, or more than 10 percent cheaper than last year's similarly structured package. Trips must be booked by Jan. 29 and taken by May 24.

"A lot of people haven't been able to afford going to the UK in a long time" because of expensive airfares and the unfavorable exchange rate, Banas said. But yesterday, the dollar hit a 23-year high against the British pound. "London is definitely the better value right now," she said.

Airfare isn't the only thing that's on sale. Cruise lines and hotels are also offering deals to boost travel.

Princess Cruises is touting its "2-for-1 Escape the Economy" for Alaskan and European cruises in marketing e-mails that tell customers "fares haven't been this low in years." The sale cruises, including a nine-day trans-Atlantic Portugal cruise that now starts at $445 per person, must be booked by Feb. 28.

In the Caribbean, Costa Cruises is letting kids sail for free through early March. Other cruise lines, such as Crystal Cruises, Disney Cruise Line, and Holland America Line, are offering free or discounted on-board services, shore excursions, room upgrades, air travel, and other rewards.

"The cruise industry is under severe strain," said Stuart MacDonald, chief executive of tripharbor.com, a cruise website. He estimates this year's winter cruises are priced 15 to 20 percent less than they were last winter, in part because the industry has stripped away its fuel surcharges. "Suppliers are reducing prices in order to stimulate demand, which will likely make 2009 the best year for deals in recent memory, should you choose to cruise."

Hotels also are discounting heavily. The Four Seasons Hotel San Francisco, for example, is giving guests their third night free through April 1, while Four Seasons Resort Maui is making the fifth consecutive night complimentary for most of the year.

The Cape Codder Resort & Spa in Hyannis is reducing rates on all rooms by 40 percent for residents of Barnstable County (and 25 percent off for everyone else) during the last week of January.

And hotels in New York have filled up three full pages of Travelocity's website with deals ranging from 10 percent off - like the $269 per night room at W New York Hotel - to 40 percent off - like the $167 per night Tudor Hotel New York.

"New York is definitely on sale right now," said Brown, the Travelocity editor. "The first quarter has always been the slowest time of year in New York, but these deals are unheard of."

The deals are even better at Steinhatchee Landing Resort, about an hour's drive from Gainesville, Fla. Guests staying at least two nights pay half-price. A year ago, the resort didn't offer any discounts.

"The desire to travel - to really get away and relax - doesn't just go away in a tough economy," Dean Fowler, the resort's developer, said in a statement.

"People need a break, so we decided to meet our guests halfway by offering them half off."